I'm guessing because taxpayers, as a rule, don't get a say in how their money is spent. Personally, I wouldn't want my money going into paying for royal weddings, legally-dubious wars or paying off foreign drug lords in the name of diplomacy or whatever, but until the forms come printed multiple-choice there's not much I can do about it.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'